Storage capacity: 4L/244cu in; Reflective details enhance visibility in low-light conditions; Bladder compartment holds up to a 1.5L bladder (sold separately); Rear stretch mesh pocket fits layers, gear, and larger essentials, plus an elastic pole keeper; Large back pocket and separate bladder compartment with hook and loop keepers; Four expandable power mesh pockets on the front straps; Designed with adjustable front and side straps to comfortably fit a wide range of body types; Two 14oz/414ml NATHAN x HydraPak QuickStart Soft Flasks included with a Push-Pull Bite Valve